• Title/Summary/Keyword: summer

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Effects of Crustal Species on Characteristics of Aerosols: Simulation of Measurements at Kosan, Cheju Island, 1994 (토양 성분이 입자 특성에 미치는 영향: 제주도 고산에서의 1994년 측정결과 모사)

  • 김용표;문길주
    • Journal of Korean Society for Atmospheric Environment
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    • v.12 no.3
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    • pp.289-296
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    • 1996
  • Effects of crustal species on the characteristics of ambient particles were studied by applying a gas-particle equilibrium model, SCAPE, to the measurements at Kosan, Cheju Island during the spring and summer, 1994. Two cases were simulated; the measured composition was used without any modification (case 1), and the metal ion concentrations originated from crust were subtracted from the measured particle composition (case 2). Total suspended particles (TSPs) were collected by an automatic high volume tape sampler during spring period and by high volume samplers during summer period. The fine particles, PM 2.5, and gaseous volatile species were collected using a filter pack smapler during summer period. The water soluble ion concentrations were analyzed from all the particle samples. According to the simulation results, the effect of crustal elements on the chemical composition of particles is negligible for both TSP particles and PM 2.5 particles. Acidity of particles measured at Kosan, however, is affected by the change of the concentrations of crustal species, stronger effects for TSP particles than for PM 2.5 particles during summer, and stronger effects during summer than spring for TSP particle. The average pH decrease due to the absence of crustal species was about 0.10 for PM 2.5 particle during summer and 1.51 and 0.85 for TSP particles during summer spring, respectively. Water contents of PM 2.5 particles for both cases are comparable to each other. Estimated water content of TSP particles for case 2 is higher than that for case 1 by about 4 $\sim 6 \mum/m^3$ because salts of metal ions are not hygroscopic.

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Comparison of Summer Turf Performance, Color, and Green Color Retention among Cool-Season Grasses Grown under USGA Soil System (USGA 지반구조에서 한지형 잔디의 여름 고온기 적응력, 색상 및 연중 녹색 유지기간 비교)

  • Kim Kyoung-Nam
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.5 s.112
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    • pp.83-93
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    • 2005
  • Research was initiated to investigate turf performance under USGA soil system. USGA system 45 centimeters deep was built with rootzone layer, intermediate layer, and drainage layer. Six turfgrass entries were comprised of 3 blends and 3 mixtures from cool-season grasses (CSG). Turfgrass color and quality ratings were best in spring and fall, especially early May to early July and late August to early November. Kentucky bluegrass (KB) consistently produced the greatest performance, while perennial ryegrass (PR) the poorest. Intermediate turf performance between KB and PR was observed with tall fescue (TF). Among CSG mixtures it increased with KB but decreased with PR. There were considerable variations in summer turf Performance. No summer drought injury was found in KB and TF. However, PR showed poor performance through summer as compared with others. Among mixtures, it decreased with PR. It was suggested that PR mix in less than $20\%$ in the mixtures to have an acceptable quality in summer. Cultural intensity also affected it. With lowering mowing height, KB of rhizomatous-type in growth habit kept good quality, while PR and TF with bunch-type in growth habit poor quality. Mowing quality was greatly different among CSG. KB produced clean-cut surface, but PR unclean one. If had an intermediate mowing quality between KB and PR. A great difference in green color retention was observed among CSG. The longest CSG was PR that kept green for 339 days, while the shortest one TF for 267 days. KB continued to keep green for 290 days. The mixtures kept green in color for 292 to 315 days, depending on turfgrass mixing intensity. The greater the PR in content, the longer the green color duration. These results demonstrate that KB was the best and PR the worst among CSG grown in USGA system under a domestic climate, in regards of turf quality, color, mowing quality, summer turf performance and green color duration. KB and TF are most adequate for high-maintenance and low-maintenance area, respectively. In case of mixtures for high-quality turf, it was desirable to use KB-based mixture with PR of below $20\%$ in seeding rate.

Wearing Comfort Evaluation of a Summer Flight Suit to Improve Ventilation (통기성 향상을 위한 하계비행복 설계 및 착용쾌적성 평가)

  • Jeon, Eun-Jin;Park, Sei-Kwon;You, Hee-Cheon;Kim, Hee-Eun
    • Fashion & Textile Research Journal
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    • v.16 no.3
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    • pp.485-491
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    • 2014
  • This study verified the effect of summer flight ventilation developed in a previous study based on wearing comfort evaluation. Seven healthy males in their twenties volunteered for this experiment conducted in aclimatic chamber. The experiment consisted of three consecutive periods of rest (20 minutes), running on a treadmill (10 minutes) and recovery (20 minutes). A comparative evaluation was conducted on the general flight suit which had no ventilation holes and summer flight suit that use subjective satisfaction measures and objective measures. The subjective satisfaction was evaluated according to the criteria of temperature sensation, wet sensation, thermal comfort and fatigue sensation. The objective satisfaction was measured by skin temperature, microclimate (temperature and humidity), sweat rate and thermography. The comparative wearing evaluation identified the summer flight suit decreased the temperature between skin and suit by $0.42^{\circ}C$ (upper arm), $0.9^{\circ}C$ (calf) and the skin temperature by $0.3^{\circ}C$ (shoulder), $0.4^{\circ}C$ (upper arm), $0.5^{\circ}C$ (calf) as compared to the general flight suit. The humidity inside the summer flight suit decreased at head (7.73%), shoulder (5.86%), upper arm (5.26%), and calf (8.73%) compared to the one inside the general flight suit. Thermography showed that the air flowed through ventilation holes (neck and armpit). The design of ventilation holes applied to the summer flight suit can be applicable to overall clothing that requires thermal comfort such as dust-free garments, mechanical clothing and combat uniforms.

A Comparative Analysis on Concentration of Pollutants in Housing Indoor-Air between Winter and Summer (주택 실내 공기중 오염물질 농도의 동절기와 하절기 비교 분석)

  • Nam, Ki-Cheul;Lee, Young-Han;Choi, Bong-Seok
    • KIEAE Journal
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    • v.17 no.3
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    • pp.125-131
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    • 2017
  • Purpose: The study is to measure concentrations of indoor air pollutants in housing and to analyze the characteristics of pollutants in housing indoor-air between summer and winter comparatively. The research result could be used as data for public health through indoor air quality management of existing housing and more as a reference for new housing. Method: It was investigated 24 middle class housings of metropolitan area in winter which have been built for the past 30 years. Concentration of HCHO, TVOC was investigated in living room at morning and night and concentration of $CO_2$ was investigated in living room and master bedroom at morning and night. SKT100-X5 was used for concentration of HCHO, TVOC and ZGm053UK for concentration of $CO_2$. The characteristics of HCHO, TVOC, $CO_2$ concentration in winter were analyzed and then the concentrations in winter were analyzed the concentrations in summer being preceding research comparatively. Result: Average concentration of TVOC in winter was 2.7 times more than that of TVOC in summer, average concentration of HCHO in winter was about 2.0 times more than that of HCHO in summer. Average concentration of $CO_2$ in the morning at living room in winter was 1.3 times more than that of $CO_2$ in summer. Average concentration of $CO_2$ in the morning at master bedroom in winter was 1.1 times more than that of $CO_2$ in summer. Average concentration of TVOC was 1.31 times more than that of HCHO and standard deviation of that was 1.73 times higher. Average concentration of $CO_2$ was almost nearly close or over to 1,000ppm being criteria of the Ministry of Environment.

Effect of age, season and sex on the blood properties in the Cheju horse (제주마(濟州馬)의 혈액성분(血液成分)에 미치는 연령(年齡), 계절(季節) 및 성(性)의 영향(影響))

  • Han, Bang-kuen;Chang, Duk-gi;Hyun, Hae-sung
    • Korean Journal of Veterinary Research
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    • v.30 no.4
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    • pp.525-532
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    • 1990
  • The values of blood composition were analyzed by age, season, and sex from Chejuhorse in Korea. The results obtained were summarized as follow; 1. The values of white blood cell(WBC), packed cell volume(PCV), mean corpuscular volume (MCV), and mean corpuscular hemoglobin concentration(MCHC) were significantly different between age. The WBC value was decreased with the progress of age and the PCV value was lower in the early age of 1,2 to 3 years than in the higher age of 4 to 5, and over 6 years. 2. The mean value of MCV was increased with the progress of age but the adverse was true in MCHC. 3. In the case of seasons, the values of red blood cell(RBC), WBC, hemoglobin(Hb) PCV, MCV, mean corpuscular hemoglobin(MCH), MCHC, globulin(Glo), albumin/globulin(A/G) ratio, inorganic phosphorus(Pi), cholesterol(Chol), and chlorine(Cl) showed significant differences. The number of RBC was not varied from winter to summer but decreased in autumn. The number of WBC was high in summer and autumn, but low in winter and spring. 4. The values of MCV were high in autumn and winter, but low in spring and summer. 5. The values of MCH and MCHC were similar in spring and summer, but strikingly increased in autumn. 6. The values of Glo and A/G ratio were negatively correlated with the season; The value of A/G ratio was lowest in summer but no differences were observed in spring, autumn and winter. On the other hand, the value of Glo was highest in summer but no differences were observed in spring, autumn, and winter. 7. The values of Pi, Chol, and CI were high in summer and winter, but low in spring and autumn. 8. The values of RBC, MCV, and MCH were significantly different between sex. The value of the RBC count in male was higer than the female, but the adverse is true in MCV, and MCH.

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Climatological Features of Summer Precipitation in Korea (우리나라 여름철 강수량의 기후적 분포 특성)

  • Jo, Ha-Man;Choe, Yeong-Jin;Gwon, Hyo-Jeong
    • Journal of Korea Water Resources Association
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    • v.30 no.3
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    • pp.247-256
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    • 1997
  • Some climatological features of summer precipitation in Korea were studyed using the precipitation data of 15 stations of Korea Meteorological Administration where more than 30 years data since 1961 are available. The study included statistical analysis of precipitation by climatological normal values, and comparison of inter-annual variation of annual precipitation, summer precipitation and precipitation during the Changma. The relationships between them were also analyzed. It was revealed that, in Korea, more than half of annual precipitation was concentrated in summer season (June to August), and it was usually influenced by the Changma. The ratio of summer and Changma precipitation to the annual precipitation showed that effect of Changma was bigger in the central inland area, while comparatively smaller in the east coastal area and Cheju Island due to topographical effects. It was also shown that the fluctuation of the annual precipitation was less variable than those of summer and Changma precipitations. Thus, it was suggested that understanding the variation features of summer precipitation associated with monsoon activities was very important to figure out the change of annual precipitation for the national water resources planning.

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Spatial Distribution Patterns of Macrobenthic Communities during Winter and Summer in the Masan Bay Special Management Area, Southern Coast of Korea (남해특별관리해역인 마산만에서 동계 및 하계에 출현하는 대형저서동물군집의 공간분포 양상)

  • Choi, Jin-Woo;Seo, Jin-Young;Lee, Chang-Hoon;Ryu, Tae-Kwon;Sung, Chan-Gyung;Han, Gi-Myung;Hyun, Sang-Min
    • Ocean and Polar Research
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    • v.27 no.4
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    • pp.381-395
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    • 2005
  • The spatial distributions of macrobenthic communities in Masan Bay were investigated during summer and winter, 2004. A total of 104 species were sampled with mean density of $448ind./m^2$ and biomass of $77.1g/m^2$ in winter. In summer, a total of 107 species occurred with $485ind./m^2$ and a biomass of $94.5g/m^2$. The most dominant species in winter were Paraprionospio pinnata (24.2%) among polychaetous worms and Theora fragilis (14.1%) among molluscs, but they were replaced in summer by Prionospio chirrifera (20.4%) and Lumbrineris longifolia (14.5%). The difference in species composition and abundance of benthic communities between the two seasons was due to the hypoxia in the bottom layer of the inner bay during summer, which defaunated the macrofauna of the sediments. In the winter when DO concentration increased to normoxia, the pelagic larvae of benthic fauna settled in the soft sediments, but there was a spatial gradient in values of total biomass, density, and H' and benthic pollution index (BPI): higher values were found toward the mouth of the bay. The multivariate analyses like the cluster analysis and MDS ordination showed that Masan Bay could be divided into two or four stational groups in winter and summer whether the hypoxia occurred or not. Group I consisted of sites at the inner bay and central area and Group II, sites at the bay mouth. In summer the inner bay area could be further divided into the shallow impoverished area and the deeper abiotic one.

The Effect of Seasonal Rhythm on the Gentamicin Pharmacokinetics in Healthy Volunteers (계절리듬이 겐타마이신의 약물동태에 미치는 영향)

  • Choi, Jun Shik;Kim, Jin;Baek, Chae Sun;Do, Nam Yong;Kim, Sung Hwan;Park, Young Jin
    • Korean Journal of Clinical Pharmacy
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    • v.8 no.2
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    • pp.89-94
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    • 1998
  • Seasonal rhythmic changes in gentamicin pharmacokinetics was evaluated in 10 healthy male volunteers after single intravenous 80 mg administration of gentamicin at 9:00 a.m. during summer and winter. The mean terminal half-life and AUC of gentamicin were $3.56\pm0.14\;hr\;and\;25.03\pm2.84\;{\mu}g/ml{\cdot}hr$ in winter and $3.08\pm0.41\;hr\;and\;21.84\pm2.51\;{\mu}g/ml{\cdot}hr$ in summer. The mean total body clearance $(CL_t)$ and elimination rate constant $(k_{10})$ of gentamicin was $3.17\pm0.43\;L/hr,\;0.458\pm0.06\;hr^{-1}\;in\;winter\;and\;3.66\pm0.45\;L/hr,\;0.561\pm0.07\;hr^{-1}$ in summer, The mean volumn of distribution $(V_{dss})$ of gentamicin at steady state was $12.65\pm1.09$L in winter and $12.39\pm1.25$ L in summer. Serum concentrations of gentamicin in winter were increased significantly during 4-8 hr (p<0.05) compared to those of gentamicin in summer. The elimination rate constant $(k_{10})$ of gentamicin in winter was decreased significantly $(p<0.05)$ compared to that of gentamicin in summer. The mean volume of distribution at steady state $(V_{dss})$, AUC, mean total body clearance ($CL_t$) and terminal half-life of gentamicin in the winter were increased but were not significant. The mean intrasubject fluctuations in terminal half-life, AUC and $CL_t$ between winter and summer were 8.2, 11.0 and $6.0\%$ respectively.

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Analysis on the Variability of Korean Summer Rainfall Associated with the Tropical Low-frequency Oscillation (적도 저주파 진동과 관련된 한반도 여름철 강수의 변동성 연구)

  • Moon, Ja-Yeon;Choi, Youngeun;Park, Changyong
    • Journal of the Korean Geographical Society
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    • v.48 no.2
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    • pp.184-203
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    • 2013
  • This study analyzes the variability of Korean summer rainfall associated with the tropical low-frequency oscillation using long-term observation data. From the EOF analysis, the first mode showed opposite phase between the South and the North Korea with the regime shift in rainfall variability since the mid-1990s. The summer precipitation over South Korea tends to increase in southern part during strong El Ni$\tilde{n}$o where the warm sea surface temperature extends to far eastern tropical Pacific. In weak La Ni$\tilde{n}$a, the increased precipitation directly influences from the western tropical Pacific to the mid-latitude. In June, the rainfall over South Korea is positively correlated with the Indian Summer Monsoon while in July, it is negatively correlated with the Western North Pacific Summer Monsoon. In August, highly negative correlation between the rainfall over South Korea and the Indian Summer Monsoon is found.

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